The Duolingo English Test takes about an hour, is taken at home under remote proctoring, and reports on a 10–160 scale with subscores for literacy, comprehension, conversation and production. Its defining feature is that it is adaptive: the difficulty of the next question depends on how you answered the last one.
Three consequences worth planning for.
You cannot go back. No review, no revisiting, no changing an answer. Every question is answered once and left, so second-guessing costs you the next question rather than fixing the last one.
Getting harder is a good sign. Students often panic when questions become difficult. Rising difficulty means the algorithm is estimating you higher; a test that stays easy is not a compliment.
The item types repeat in a small set, and they are unusual enough that seeing them for the first time on test day is a real handicap: read-and-complete (words with missing letters), listen-and-type (dictation), read-aloud, describe-an-image in speech, write-about-a-photo, interactive reading and writing, and the longer speaking and writing samples at the end which are sent to institutions as your video interview and writing sample.
Set-up is part of the test. It is proctored: quiet room, clear desk, ID ready, face visible and forward for the whole hour, no notes, no leaving the frame. A failed rule check can void the result after you have finished, which is a worse outcome than a low score.
For an Indian student the practical draw is cost and speed — the DET is cheaper than IELTS or TOEFL and results come back in about two days — but always confirm your university accepts it, and at what score, before booking.